In the known variable-ratio gear transmission of the type mentioned above (U.S. Pat. No. 4,658,663), the gear stages for the gears I, III, IV, and R are assigned to the first partial transmission, and the gear stages for the gears II and V and the auxiliary gear stage having the gear ratio of gear III are assigned to the second partial transmission, gear IV being designed as a direct gear and able to be shifted using gear III using a manual transmission clutch in the first partial transmission, as is also provided for the auxiliary gear stage and the gear stage of gear V upon the engagement of a manual transmission clutch in the second partial transmission. For the gear stages assigned to the five forward gears and one reverse gear, for the auxiliary gear stage and the gear constant, a total of seven gear sets are supported next to each other along the common counter shaft, so that this known variable-ratio gear transmission comes to be relatively large in the directions of the transmission shafts.